The present invention relates to a low cost system for the fabrication of storage containers, the containers so formed and the structural elements used to form containers.
Storage containers or vessels are usually fabricated from cast materials whether metal or plastic or they may be flexible containers with or without reinforcing. The following prior art is believed relevant to the present disclosure. U.S. Pat. Nos. 3,657,042; 4,277,688; 3,875,723; 4,353,763; 4,132,050; 4,409,776; 2,260,064; and 4,451,739; and European Patent 0072429.
There is a need for a vessel, container, tank or related structure that has low cost, ease of on site fabrication and particularly, a highly sophisticated custom tailored construction to match demanding specifications.
Broadly, the invention is directed to structural improvements of the container disclosed in my parent application, which application is incorporated by reference in its entirety into this disclosure.
With larger structures the compression caused by the carrier films and then subsequently by the hydraulic pressure of the water when the container is filled requires that a structure of a different design be used.
In one design, a first grid of pipe and fittings is formed. A second companion or identical grid of pipes and fittings is formed and pressure absorption blocks are disposed between the first and second grids to form a sandwich-like assembly. This sandwich-like assembly is then individually wrapped with the plastic carrier film and the wrapped assemblies subsequently joined to one another to form the bottom, sides and top of the frame. This frame is then wrapped, as is the frame of the preferred embodiment to form a `liner` as described in my parent application or a container per se.
In another design, alone or in combination with the one deisgn, specially formed pipe is used. The pipe can comprise an extruded pipe which may be round, rectangular or any desired shape, but obviously from a point of view of manufacturing, either round or rectangular is preferred. Received within the pipe is an extruded profile which can be in any geometric configuration as long as it functions in combination with the pipe to provide a pipe of increased strength. Typical extruded profiles could includes spokes, a maltese cross, an I-beam and the like. The extruded profiles can also be of the same cross sectional shape as the pipe and telescoped therein. The extruded profile can have a thin coating of an adhesive on its surface to ensure engagement with the pipe. The adhesion can be a mechanical adhesion or a chemical adhesion, such as cross-linking by polymerization. One can pick from a variety of thermoplastic/thermosetting resins to effect the bond. The pipe and extruded profile are customized to create the strongest possible fusion between the two or three concentric or telescoped elements.
Where similar pipes are used in the telescoped arrangement, the outer surface of the inner pipe can be ribbed, either in corrugated form or spirally, to enhance the bonding between the inner and outer pipes. The bonding interface can also have polymerizable resins. These can contain such reinforcing dispersions as small metallic, needle-like particles, such as iron or copper fillings or short fiberglass or carbon fiber filaments. When fully polymerized, their random orientation, embedded in the polymer matrix, will impart to the laminated extrusion greater compression and tensile strength. The polymerization can take place at room temperature or the polymerization can be accelerated by passing the assembled components into a heat exchange zone, such as by the use of microwave or high-frequency radiation.
In another preferred embodiment, the container is used as an anaerobic digester. The container is filled with the material to be digested. Concentric pipes are received in the container to introduce nutrients, fluids and other additives into the digester and the liquid and methane formed in the digester is removed.
In another embodiment of the invention, a panel is uniquely adapted for use in a greenhouse-like structure. A single or double pipe frame may simply be wrapped with clear stretch film. Water or other heat exchange fluids can flow through the pipe and/or into a chamber within the panel. The panels may be assembled such that water or other heat exchange fluids, including as gases, be transferred from one panel to another.